Importance of surface hydrogen concentration in enhancing activity of CoNi alloy catalyst for CO hydrogenation

Abstract

The hydrogen—deuterium exchange reaction was employed for studying the reactivity of adsorbed hydrogen on CoNi alloy. The infrared spectra of adsorbed NO indicates that the support oxide electronically interacts with the CONi alloy. Desorption measurements suggest that the electron density of the alloy greatly influences the surface coverage of hydrogen and carbon monoxide. The CO hydrogenation rate of CoNi alloy in the presence of CO was shown to be related to the H 2D 2 exchange rate. The dissociative adsorption of hydrogen in the presence of CO is of primary importance in determining the CO hydrogenation rate of the CoNi alloy system, since the preadsorbed CO species strongly hinder the hydrogen adsorption. A high surface concentration of active hydrogen in the presence of CO leads to high catalytic activity for CO hydrogenation on CoNi alloy.